Toxic effects of repeated oral exposure of silver nanoparticles on small intestine mucosa of mice.

As the use of silver nanoparticles (AgNPs) is increasing fast in industry, food, medicines, etc., exposure to AgNPs is increasing in quantity day by day. So, it is imperative to know the adverse effects of AgNPs in man. In this study, we selected mice as an animal model and observed the effect of AgNPs on small intestinal mucosa. AgNPs ranging from 3 to 20 nm were administered orally at a dose of 5, 10, 15 and 20 mg/kg body weight to the Swiss-albino male mice for 21 d. There was a significant decrease (p < 0.05) in the body weight of mice in all the AgNPs-treated groups. Mice treated at a dose of 10 mg/kg showed the maximum weight loss. Effects were noted by using light microscopy as well as transmission electron microscopy. It was found that AgNPs damage the epithelial cell microvilli as well as intestinal glands. It may be hypothesized that loss of microvilli reduced absorptive capacity of intestinal epithelium and hence weight loss.